A 61-year-old doctor contracted both the Alpha and Delta variants at various stages

The Heart Care Foundation of India (HCFI) Dr KK Aggarwal Research Fund has documented severe SARS-CoV-2 breakthrough reinfection with Delta variant after recovery from a breakthrough infection by Alpha variant in a fully vaccinated healthcare worker. Currently under study, the case in point is that of a 61-year-old doctor from Delhi in whom the Delta variant infection resulted in hypoxia, hospitalization, and illness lasting seven weeks.

The second and third infections occurred after the doctor had taken both the vaccine shots and developed antibodies. The term “breakthrough reinfection” has been specifically coined for this, and it is also the first proven case of the same. The doctor was first infected in August 2020. The study done on this case will soon be published in an international peer reviewed medical journal called Frontiers in Medicine.

Speaking about this, Dr Veena Aggarwal, Trustee HCFI and co-author of the study said, “The study conducted identifies a rare breakthrough infection that was also confirmed as a reinfection. The breakthrough reinfection was severe enough to result in hypoxia and hospitalization and was contracted from a fully vaccinated family member. The Ct values in the Delta variant breakthrough reinfection were low enough to suggest transmission potential. This reinforces the recommendation that fully vaccinated individuals should continue to take precautions to protect themselves and others.”

Adding further, Dr. Jayanthi S. Shastri Head, Molecular Diagnostic reference Laboratory Kasturba Hospital Mumbai for Infectious diseases and Lead Researcher of the study said, “There are certain criteria laid down by CDC and ICMR for reinfection. They indicate that there has to be an infection on two different occasions, which are 45 to 90 days apart as per CDC and 102 days according to ICMR. This can be detected only if a person has access to whole-genome sequencing. A study conducted by ICMR indicates that the possibility of reinfections currently stands at 4.5%.”

There is no definite data on reinfections currently since whole-genome sequencing is not accessible and expensive. Labs also do not have much access to samples. As per the study conducted, post-infection and post-vaccination immunity both confer protection against COVID-19. However, there have been many whole-genome sequencing proven and breakthrough infections. Both are most often mild and caused by variants of concern (VOC).

Breakthrough infections happen when people get infected after vaccination because the virus broke through the protective barrier the vaccine provides. The need of the hour is not to ignore symptoms, follow all the safety protocols even after both vaccination doses. This is more so in the case of individuals with other underlying healthcare conditions.

India’s COVID numbers stand at 30 million with over 4 million active cases. Given the likelihood of reinfections, there is a need for further research. It is also imperative for people to come forward and report any such instances to HCFI Dr KK Research Fund (www.drkkshcfi.org) for further studies on the subject.